Grinding and polishing machine



INVENTOR LOU/5 lav/5,3 an. BY 7 ATTORNEY L KNKEP, JR

GRINDING AND POLISHING MACHINE Fllcd March 27, 1950 March 31, 15 53 Patented Mar. 1953 UNITED" STATES PA ENT OFFICE GRINfiING Ann POLISHING MAcHiNE Louis Kniep, Jr., Dover, N. J. Application March 27, 1950, serial No. 152,107

12' Claims.

This invention relates to surfacing machines and more particularly to grinding, sanding, but: ring and polishing machines of the belt type.

Surfacing and polishing machines of the endless belt type, heretofore proposed, usually include some form of adjustment or an arrangement of springs to maintain the belt under tension. Many such proposed machines are either too elaborate and therefore commercially impractical or they require frequent adjustment.

One of the objects of this invention is to provide a machine of the endless belt type which is relatively simple yet sturdy in construction and capable of maintaining automatically a desired tension upon the work belt.

Another object of the invention is to provide a surfacing and polishing" machine of the endless belt type capable of increasing tension upon the belt in accordance with increased pressure exerted thereagainst by a work piece being sur faced and polished.

-One of the features of the invention lies in the manner of supporting the rollers or pulleys which support the endless belt. One of the rollers is mounted at one end of a support while the other'roller' is mounted on the end of a second support, the two supports being disposed crosswise or each other and pivotally' connected together at a central cross-over point. The base end of one of the supports is pivotally connected to a base while-the base endof the other support is freely slidable; within limits, on the base-.- This mounting arrangement provides tension on the work belt since the belt is necessary to keep the roller supporting ends of the supports from spreading. In other words, the weight of the two supports and the rollers thereon provide a tension. force upon. the belt. In addition, this mounting: arrangement also renders it easy to replace or interchange different types of work belts; such as abrasive, buffing and polishing types by merely pivoting the roller supports toward each other.

A further feature of the: inventionis the'motor.

drive for the endless work belt whereby additional tension force is exerted: on the belt; The motor is mounted on a pivot which may comprise the; same pivotal connectionfor the two, roller supports, the motor being coupled by a driving belt extending about a pulley carried by the shaft of the motor .and a pulley carried by the shaft of one of the rollers. The motor is disposed to one side of the pivot so that the weightof the motor exertsv tension. uponthe driving; belt and at the same time exerts through the pivot and the driv- (O1. Sla 135) ing belt an additional tensioning force upon the work belt.

Still another feature of the invention is the provision of a removable table provided with foot ings receivable on the pivoted supports for positioning of the table between the rollers and beneath the endless work belt.- Iri this position the table provides a backing for the belt when work pieces are applied thereto. Such a backing is particularly desirable where flat surf-aces are to be ground and polished. When curved surfaces are to be ground or polished the table is removed, thereby permitting the belt to assume a curvature in accordance with the pressure applied thereto.

The foregoing and other objects and features of the invention will become more clearly understood upon consideration of the following detaileddescription and the accompanying draw-- ing, in which:

Fig.- l is a view in side elevation of a preferred embodiment of a surfacing and polishing machine according to my invention; and i Fig. 2 is a view in plan of the machine with parts shown in section,

Referring to the drawing, the surfacing andpolishing machine includes abase 10' having one or more bearing elements. I4 inthe form of upright projections located adjacent the upper left hand edge thereof. A first support. I6 is adapted to rest either upon bearing elements M or upon the upper surface of the base [0 in abutting relation against the elements [4, for reasons hereinafter explained. A second roller support I! is piv'otall supported by a bolt 18 on the base Ill adjacent the right hand edge thereof. The first and second supports it and I! are similarly con structed, the support l6 comprising two legs l9 and 20 held. together by tie bolts 2| and 22, and support I! comprising two legs 23 and 24 held together by a tie bolt 25. The legs of the two. supports are angularly shaped and disposed crosswise of each other and pivotally connected together by a pivot rod 26 extending therethrough at a point a distance from the ends thereof.

The upper ends of the side members [9, 2!] and 23, 24 are eachrecessed as indicated at 2 1 to receive one of thebearings 28 which support rollers 3| and 32. The legs 23 and, and also legs 19 and 20, if desired, are each provided with a threaded opening 29 which extends into the recess 21 to accommodate a set screw 34 for ad.- justing the location of the bearings 28 within the recesses 21; .An endless won; belt 33 sur rounds the two rollers, and since the legs of the two supports l6 and I! are pivotally supported the belt 33 holds the support from dropping down on the base.

From the foregoing it will be observed that when the legs l9 and 20 rest in sliding relation upon the bearing elements l4 the weight of the support members l6 and I! together with the weight of the rollers 3| and 32, and any pressure exerted against the work belt by a work piece, tend to spread or collapse the pivoted supports l6 and I! thereby exerting tension on the belt 33.

This tensioning of the belt 33 is further supplemented by the driving arrangement of the motor 35. The motor is mounted on a bracket 36 pivotally supported on rod 26. The motor 35 is provided with a drive pulley 31 which accommodates a belt 38 receivable on a pulley 39 carried by the shaft 40 of roller 3|. The belt 38 is of such a length that the bracket 36 is normally swung to an angular position with respect to the vertical so that the weight of the motor not only tensions the driving belt 38 but also provides a downward force on the roller 3| thereby further tensioning belt 33. Thus, during operation of the surfacing and polishing machine the belt 33 is maintained under tension and any pressure tending to force the belt 33 downwardly increases this tension since a forcing downwardly of the belt pulls the rolls 3| and 32 toward each other thereby lifting the motor counterclockwise about the pivot rod 36.

While the motor 35 is shown pivoted on rod 26 it may, of course, be mounted on a separate pivot either on one of the supports IE or I! or upon the base l0. It is preferable, however, to have the motor pivotally supported on rod 26 since in this position the weight of the motor is applied to the supports l6 and I1 both through the pivotal connection and pulley 39.

Where it is desirable to maintain the belt 33 perfectly flat for surfacing and polishing fiat surfaces I provide a table 4| having two side members such as indicated at 42, the corners of which are provided with lateral projections 43 adapted to rest upon the inclined upper surfaces of the side members |9, 23 and 23, 24. The corners 44 serve to center the table on the legs of the supports l6 and H. The table may be positioned on the legs by shifting the support l6 so that the lower ends of the legs I9 and 20 rest on the base It to the right of the bearing elements l4. This lifts the rollers 3| and 32 upwardly and toward each other thereby providing slack in the belt 33 to permit insertion or removal of the table 4| beneath the belt. By lifting the support l6 so that the lower ends of the legs H) and 20 rest upon bearing elements l4, the supports l3 and I! will assume a position exerting tension upon the belt 33 with the table 4| in position to provide a fiat base for the belt. Should the belt 33 become worn or torn so as to separate, stops 45 on legs l9 and 20 will engage elements l4 and thereby limit the collapsing tendency of the supports l6 and H. A new belt may be applied by placing the ends of the legs I9 and 20 against the bearing elements |4.

While I have described the principles of my invention in connection with a particular embodi ment it will be clear that many variations may be made without departing from the invention. The legs I9, 20 and 23, 24, for example, may have shapes quite different from that shown and yet be pivoted together for the same purpose heretofore described. It is to be understood there- '4 fore that this description is given as illustrative of the invention only and not as restrictive of the scope of the appended claims.

I claim:

1. A surfacing and polishing machine comprising first and second rollers, an endless work engaging belt carried by said rollers, a first support disposed with one end up and the other end down, a second support disposed with one end up and the other end down, said first and second rollers being carried by the upper end portions of said first and second supports, respectively, a base, means pivotally supporting the lower end portion of said-first support on said base, and means pivotally supporting said second support on said first support with the lower end portion of said second support in engagement with said base.

2. A machine according to claim 1 wherein said first and second supports are disposed crosswise of each other and said means pivotally connecting the supports together includes pivot means at the crossover portions of said supports.

3. A surfacing and polishing machine comprising first and second rollers, an endless work engaging belt carried by said rollers, a first support for said first roller, a second support for said second roller, a base, means pivotally supporting said first support on said base, means pivotally connecting said second support to said first support, said second support having a part extending beyond its pivot connection in engagement withsaid base, said base having a bearing element, and the portion of said second support extending beyond the pivotal connection thereof being adapted for relative movement on said bearing element during operations requiring tensioning of said belt and for abutting relation with said element when it is desired to hold said belt in a slack condition.

4. A surfacing and polishing machine comprising first and second rollers, an endless work engaging belt carried by said rollers, a first support for said first roller, a second support for said second roller, a base, means pivotally supporting said first support on said base, means pivotally connecting said second support to said first support, said second support having a part extending beyond its pivot connection in engagement with said base, a motor, a belt coupling said motor in driving relation with said first roller, and means mounting said motor on one of said supports, whereby the weight of said motor tends to spread said supports at the ends supporting said rollers thereby tensioning said work engaging belt.

5. A machine according to claim 4 wherein one of the pivotal connection-s includes a .pivot pin and said means for mounting said motor includes a bracket pivotally supported on said pin, whereby the weight of said motor not only tensions the drive belt but also acts through the drive belt to apply leverage on the support supporting said first roller, thereby tensioning said work engaging belt.

6. In combination a base, a support having legs disposed crosswise of each other, a pair of rollers, one each supported by the upper end portion of each of said legs, said rollers being adapted to receive an endless work engaging belt thereabout, means pivotally connecting said legs together at the crossover portions thereof and means pivotally connecting the lower end of one of said legs at a given point to said base, the

by the weight of said motor tends to spread the upper ends'of said supports and thereby tension said work engaging belt.

8. A combination according to claim 6 further including a table platform and means for "re-H] movably supporting said platform on the legs of,"

said support in underlying relation with respec to saidgwork, engaging belt.

9. A combination according to claim 6 whe ein each leg of said support comprises a pair of side members with spacer pieces rigidly connecting said side members.

10. A combination according to claim 9 wherein the means for pivotal-1y connecting the legs together includes a pivot pin extending through the side members of said legs, and which further comprises a bracket pivotally mounted on said pin, a motor carried by said bracket and means including a driving belt for coupling said .motor in driving relation with one of said rollers, said belt being of a size to pivotally swing said bracket to an angular position with respect to the vertical whereby the weight of the motor applie tension to said driving belt and to said work engaging belt.

11. A combination according to claim 6 wherein said base includes a bearing element to slide- 6 ably support said other leg and against which said other leg may be lodged to reduce the distance between the said rollers and thereby slacken said work engaging belt.

12. In a machine having an endless work engaging belt supported by a pair of rollers, means for maintaining tension upon said belt, said means comprising a pair of supports, one for each roller, said rollers being carried by the upper end portions of said supports, each said support being disposed with 'one end thereof higher than the other end thereof with means p'ivotally supporting one of said supports at the lower end thereof, means pivotallyconnecting together the mid-sections of said supports, and means slideably supporting the lower end of the other of said supports.

LOUIS KNIEP, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

